C:N:P Stoichiometric Characteristics Of Soil And Litter Of Broad-leaved Forest In Longxi-Hongkou Reserve

The balance of elements in the ecosystem has become a hot research topic. In the forest ecosystem, soil and litter is closely related to each other, and the flow and coordination process of nutrient elements between them more get the attention of researchers. Through the research that characteristics in carbon, nitrogen and phosphorus contents in soil and litter of broad leaved forest in Longxi-Hongkou national nature reserve, try to clarify the relationship in study area of the forest litter and soil carbon (C), nitrogen (N) and phosphorus (P) coupling relationship, and the effects of altitude on litter and soil ecological stoichiometry, The judgment of soil nutrient elements. The main results obtained were as follows:1. In the study area, the C, N and P content of soil and litter increased with the rise of elevation. The content of C, N and P in soil and litter was significantly positively correlated with altitude (P< 0.01), but there was no correlation between the stoichiometric ratio of soil and litter to the altitude (P> 0.05). In the 0-20 cm layer soil, there was significant correlation between C:N, N:P and N:P ratios and elevation in evergreen broad-leaved forest (P< 0.01), while a significant correlation between C:P ratio and altitude (P< 0.01) was found in evergreen broadleaf and deciduous mixed forest. In the 20 - 40 cm layer soil, there was a significant correlation between C:N ratio and altitude in evergreen broadleaf and deciduous mixed forest (P< 0.01). In different forest, litter C:N ratio were significantly negatively correlated with altitude (P< 0.05), whereas the litter N:P ratio significantly positively correlated with altitude (P< 0.05). These results indicated that the effect of altitude on the decomposition rate of litter could be promoted.2. The C content of soil in our research forest area was relatively high, compared to the forest around the country. The higher soil C:N ratio in evergreen broad-leaves forest was observed, showing a slow decomposition rate of the litter, a slow mineralization rate in soil nutrients as well as slow nutrient cycling speed. The value of N:P for litter under broad leaved forest was 15.03, which is between 14 and 16. It was suggested that the nutrition in this region is mainly affected by the limitation of nitrogen and phosphorus.3. There was a significant correlation between soil and litter in C, N and P content (p< 0.01). However, the content of N and P was notably correlated with C:N:P stoichiometry in litter (P< 0.05). In evergreen broad-leaved forest, a significant correlation (P< 0.05) between C, N and P content in litter and stoichiometric ratio of soil with 0-20 cm layer was recorded. In addition, the C, N and P content in litter also remarkably correlated with C:N ratio in 20 - 40 layers soil in the evergreen and deciduous broadleaf mixed forest (P< 0.05). This might result from the greater return of litter in evergreen and deciduous broadleaved mixed forest.